Versatile uninterruptable power supply

ABSTRACT

Systems, apparatuses, and methods are described for a versatile UPS. The versatile UPS is operative to provide power to a load and to an interconnected network for delivering electricity from producers to consumers (i.e., an electricity grid, or simply, “a grid”). The versatile UPS has a plurality of switches providing for a multiplicity of switching states. The output to the load, the grid, or both is dependent, at least in part, on the switching states. Related systems, methods and apparatus is also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/149,894, filed Jan. 15, 2021, which is a non-provisional of andclaims benefit of U.S. Provisional Patent Application No. 62/961,546,filed Jan. 15, 2020, which are hereby incorporated by reference in theirentireties.

BACKGROUND

An uninterruptible power supply (UPS, sometimes referred to as anuninterruptible power source) is one of a category of power supplyingdevices that provides power to a load upon failure of an input powersource, such as a power grid. UPS devices typically provide protectionfrom input power interruptions by providing the load with power, whichis typically stored in a battery, a super-capacitor, a flywheel, orother appropriate energy storage device.

Run-time of the UPS may be short (typically limited by storage capacityof the battery, super-capacitor, flywheel, or other appropriate storagedevice), but may provide sufficient time to either restore power fromthe power grid or to properly shut down the load.

SUMMARY

The following summary presents a simplified summary of certain features.The summary is not an extensive overview and is not intended to identifykey or critical elements.

Systems, apparatuses, and methods are described for a versatile UPS. Theversatile UPS may be operative to provide power to a load and/or to aninterconnected network for delivering electricity from producers toconsumers (e.g., an electricity grid, or simply, a/the “grid”). In sucha case, power may be sold to an owner or operator of the grid by theconsumer. The versatile UPS has a plurality of switches providing for amultiplicity of switching states. The output to the load, the grid, orboth is dependent, at least in part, on the switching states.

These and other features and advantages are described in greater detailbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

Some features are shown by way of example, and not by limitation, in theaccompanying drawings. In the drawings, like numerals reference similarelements.

FIG. 1 shows an example UPS;

FIG. 1A is a flow chart providing an example of operation of the UPS 100with the UI 180;

FIG. 2 is a flow chart of an example method for operating a UPS;

FIG. 3 is a flow chart of an example method for controlling modes ofoperation of a UPS;

FIG. 4 shows a second example of a UPS;

FIG. 5 is a flow chart of operation of the UPS device 400 as a switch;and

FIG. 6 is an example block diagram of an architecture of a controllerfor a UPS such as the UPS of FIG. 1 or 4 .

DETAILED DESCRIPTION

The accompanying drawings, which form a part hereof, show examples ofthe disclosure. It is to be understood that the examples shown in thedrawings and/or discussed herein are non-exclusive and that there areother examples of how the disclosure may be practiced.

Reference is now made to FIG. 1 , which shows an example of a UPS 100.The UPS 100 comprises a first terminal 110 for receiving a firstalternating current (AC) electricity input, for example, from anelectrical power grid (e.g., an interconnected network for deliveringelectricity from producers and suppliers to consumers). The firstterminal 110 may be connected to a first power converter 120, whichincludes an AC terminal and a direct current (DC) terminal. The firstpower converter 120 converts AC electricity received on the AC terminalfrom the first AC electricity input to direct current (DC) electricityon the DC terminal. The first power converter 120 may comprise abidirectional inverter that also converts DC electricity received on theDC terminal to AC electricity on the AC terminal. A first switch SW1 maybe disposed between the first terminal 110 and the AC terminal of thefirst power converter 120. SW1 may comprise any of a relay, a transistor(for example, a MOSFET or an IGBT), a contactor switch, or any otherappropriate switch. The operation of the first switch SW1 is describedbelow. A second switch, SW1.1 may also be included in series to SW1(e.g., between SW1 and the AC terminal of first power converter 120). Afirst silicon controlled rectifier (sometimes referred to as asemiconductor-controlled rectifier) (SCR), labelled CR1 in FIG. 1 may beconnected in parallel with SW1.1. As with SW1, SW1.1 may comprise any ofa relay, a transistor (e.g., a MOSFET or an IGBT), a contactor switch,or any other appropriate switch. The term first switch circuit as usedherein means the switch SW1, the switch SW1.1, and the SCR CR1.Similarly, the term second switch circuit as used herein means theswitch SW2, the switch SW2.1, and the SCR CR2.

The first silicon controlled rectifier, CR1 (and a second siliconcontrolled rectifier, CR2, discussed below), are depicted as twoanti-parallel silicon controlled rectifiers. Such an arrangement enablesCR1 and CR2 to function as a switch, enabling the UPS device 100 toeffect a near instantaneous transition from providing power from one ormore of the AC power sources to a load 150 (described below) toproviding power from a battery 130 (described below) to the load 150.

The first power converter 120 may comprise a bidirectional inverter andmay process DC power, which may be stored in the battery 130, and mayprocess AC power provided by a grid or AC power provided to the load,for example 150. The load 150 may connect to the UPS 100 at a terminal,for example terminal 190. Terminal 190 is depicted as being in the UPSdevice 100, although in practice, the terminal may be disposed in anexternal wall of the UPS device 100, or externally to the UPS device100. The term “battery” as used herein refers to any appropriate energystorage device, for example, an electrochemical battery (e.g., Li-ionbattery), a fuel cell, a super-capacitor, a flywheel, etc. In one modeof operation, the first power converter 120 may operate as an inverter,converting DC electricity (e.g., from the battery 130) to ACelectricity. In a second mode of operation, the first power converter120 may operate as a DC-to-AC converter (e.g., a full-bridge rectifier,buck converter, boost converter), converting AC electricity (e.g., fromthe grid) to DC electricity. The battery 130 may serve as a source ofauxiliary power when the UPS needs to provide power at an output, aswill be described below. The battery 130 and a DC terminal of the firstpower converter 120 connect to a common terminal T1. Common terminal T1may be further connected to a second power converter 140. The secondpower converter 140 may comprise a bidirectional inverter, which in afirst mode of operation, may operate as an inverter, converting DCelectricity (e.g., from the battery 130) to AC electricity (which may beprovided to the grid, as explained below). In a second mode ofoperation, the second power converter 140 may operate as a AC-to-DCconverter, converting AC electricity (e.g., from the grid) to DCelectricity, similar to the first power converter 120. An AC terminal ofthe second power converter 140 may be coupled (e.g., connected viaswitches) to the load 150. In response to no first AC electricity inputbeing received at the first terminal 110 (e.g., because of a powerfailure), the first power converter 120 and/or the second powerconverter 140 may provide power to load 150, for example by convertingDC electricity from battery 130 to AC electricity. Using this electricalpower, for example, load 150 may continue operation until either inputAC electricity is restored, the load 150 may be shut down, or thebattery 130 drains to a point where the load 150 may be unable tooperate further. The load 150 may be within a specified rating of theUPS 100. Namely, if the UPS is rated to provide output power of 18 kVA,then for example, power requirements of the load 150 does not exceed 18kVA.

In one mode of operation, the first power converter 120 and/or thesecond power converter 140 may each operate as an AC-to-DC converter,converting AC electricity received on the AC terminal to DC electricityon the DC terminal. In a second mode of operation, each of the firstpower converter 120 and/or the second power converter 140 may operate asa DC-to-AC circuit (also known as an inverter circuit), converting DCelectricity received on the DC terminal to AC electricity on the ACterminal. A controller 170, may control the modes of operation of thefirst power converter 120 and/or the second power converter 140 of theUPS 100, for example by controlling modes or states of the first powerconverter 120, the second power converter 140, and/or circuitries ofswitches (such as CR1, CR2, SW1, SW1.1, SW2, SW.2.2, and/or SW3).Alternatively or additionally, controller 170 may comprise a high-levelcontroller, which controls a plurality of lower-level controllers, suchas controllers 172, 174, 176 shown in FIG. 1 . Elements controlled bylower-level controllers 172, 174, 176 are, for example, surrounded by adotted line forming a rectangle. First lower-level controller 172 mayreceive one or more operational commands (e.g., signals, messages) fromthe high-level controller 170, for example, regarding states ofoperation of the UPS 100 and/or states of operation of a first switchcircuit (such as CR1, SW1 and/or SW1.1). The first lower-levelcontroller 172 may then operate the first switch circuit (such as SW1,SW1.1, and CR1), configuring them appropriately to a particular mode ofoperation (described below). Additional lower level controllers (notdepicted) may control modes of operation of the first power converter120, and the second power converter 140 based on commands fromcontroller 170.

The UPS 100 may comprise a second terminal 160 for receiving a second ACelectricity input from, for example, the electrical power grid (similarto first terminal 110). The second terminal 160 may be connected to aswitch SW2 which, when closed (ON), connects the second terminal 160 tothe load 150, for example, thus providing AC electricity directly to theload. SW2 may, in some examples of operation, be connected to theelectrical power grid via the first terminal 110. In such a case,however, power provided at the first terminal 110 would need to bedouble what it would be in a case where SW2 is connected to theelectrical power grid via the second terminal 160. Another switch,SW2.1, may also be included in series to SW2 (e.g., between SW2 and theload 150). A second SCR, labelled CR2 in FIG. 1 may be connected inparallel with SW2.1. SW2 and SW2.1 may comprise any of a relay, atransistor (e.g., a MOSFET, an IGBT), a contactor switch, or any otherappropriate switch. Second lower-level controller 174 may receive one ormore operational commands (e.g., signals, messages) from the high-levelcontroller 170, for example, regarding states of operation of the UPS100 and/or states of operation of a second switch circuit (such as CR2,SW2 and/or SW2.1). The second lower-level controller 174 may thenoperate the second switch circuit (such as SW2, SW2.1, and CR2),configuring them appropriately to a particular mode of operation(described below).

In some variations of the system in FIG. 1 , a conduction path may beprovided and comprises a third switch SW3 connected between the ACterminal of circuit 120 (or to switch 1.1) and the AC terminal ofcircuit 140 (or to load 150), the operation of which may be explainedbelow, along with the operation of UPS 100. For example, the conductionpath bypasses circuit 120 and circuit 140. SW3 may comprise any of arelay, a transistor (e.g., a MOSFET, an IGBT), a contactor switch, orany other appropriate switch. Third lower-level controller 176 mayreceive one or more operational commands (e.g., signals, messages) fromthe high-level controller 170, for example, regarding states ofoperation of the UPS 100 and or states of operation of SW3. The thirdlower-level controller 176 may then control the operation of SW3,configuring based on the one or more operational commands, for example,in accordance with a particular mode of operation (described below).

UPS 100 may operate as a standby UPS, e.g., comprising externalelectrical power source intended to replace primary power in the eventof primary power failure. A standby UPS draws AC power, for example,from a wall outlet, and switched to drawing power from a battery withina few milliseconds based on a power failure (e.g., in response todetecting a loss of AC power). UPS 100 may provide protection againsttransient voltage spikes and may provide battery backup, based on apower failure, e.g., in response to an AC power source ceasing toprovide power. Alternatively or additionally, UPS 100 may operate as anon-line UPS, in which case, UPS 100 provides power to the load 150whether or not there is an AC input. UPS 100 may be configurable tooperate in a first mode as an on-line UPS, and in a second mode, as astandby UPS. A description of an example of how the UPS 100 may beconfigured is provided below, with reference to FIG. 3 .

The controller 170, which may be programmed microcontroller (e.g., withmemory storing instructions readable by the microcontroller) or aspecially designed silicon chip (e.g., ASIC, FPGA) to operate theswitches of the first and second switch circuit (such as SW1, SW1.1,SW2, SW2.1, SW3, the CR1, CR2), as well as switches and modes ofoperation of the first power converter 120, and the second powerconverter 140. In implementations where the controller 170 comprises ahigh level controller, as discussed above, and the various switches ofthe first and second switch circuit (such as SW1, SW1.1, SW2, SW2.1, andSW3) are controlled in one variation, respectively by first lower-levelcontroller 172, second lower-level controller 174, and third lower-levelcontroller 176. The first lower-level controller 172, the secondlower-level controller 174, and the third lower-level controller 176 maybe an appropriately programmed microcontroller (e.g., with memorystoring instructions readable by the microcontroller) or a speciallydesigned silicon chip (e.g., ASIC, FPGA) to operate the switches SW1,SW1.1, SW2, SW2.1, SW3, the CR1, CR2. While lower-level controllers 172,174, and 176 are illustrated in FIG. 1 for controlling certaincomponents of UPS 120, other variations may include more or lesslower-level controllers, each controlling different combinations of SW1,SW1.1, SW2, SW2.2, SW3, 120 and/or 140.

Alternatively or additionally, a data communication signal may be used,for example, over a wired or a wireless network, to deliver a command toenter into or change from one particular mode of operation of the UPS100 to another. Still further alternatively, a device having computingpower (e.g., microcontroller and memory storing instructions executableby the microcontroller) may control the choice of mode of operation ofthe UPS 100 without a hum an user intervening in the control of the UPS100.

In accordance with the above, examples of switching states may besummarized as follows, in Table 1 and Table 2. In Table 1, a one (1)indicates either a closed switch state or an operative SCR state, asappropriate to a given cell. A zero (0) indicates either an open switchstate or a non-operative SCR state, as appropriate to a given cell.

TABLE 1 Operation Mode Description SW1 SW1.1 CR1 SW2 SW2.1 CR2 SW3 FirstMode Normal mode, On-line 1 1 0 1 0 0 0 UPS Second Bypass mode, On-line1 1 0 1 0 1 0 Mode UPS Third Backup mode, double 0 0 0 0 0 0 1 Modepower, standby UPS Fourth Backup mode, single 0 0 0 0 0 0 0 Mode powerFifth Energy storage mode, 1 1 0 1 1 0 0 Mode double power Six Energystorage mode 1 0 1 1 0 1 1 Mode double power with UPS ability SeventhBackup mode and 1 1 0 0 0 0 0 Mode Energy Storage Together EighthPartial Energy storage 1 1 0 1 0 0 0 Mode mode with a single power UPS(option 1) Ninth Partial Energy storage 0 0 0 1 1 0 0 Mode mode with asingle power UPS (option 2) Tenth Energy path only to 0 0 0 1 0 1 0 ModeAC 2

In Table 2, operation of the first power converter 120 and the secondpower converter 140 are described as converting AC power to DC power(AC/DC) or as being in standby mode. The source of power to the load 150identifies whether power is provided to the load 150 from AC1, AC2, thebattery 150, or some combination of all or some of AC1, AC2, the battery150. Battery state specifies the operation of the battery in a givenmode, for instance, charging, discharging, or no operation.

TABLE 2 Operation First Power Second Power Source of Power Battery 130Mode Description Converter 120 Converter 140 to Load 150 State FirstNormal mode: AC/DC DC/AC From AC1 Charging or Mode On-line UPS and/orbattery discharging or nothing Second Bypass mode, AC/DC STANDBY AC2Charging Mode On-line UPS Third Backup mode, DC/AC DC/AC Battery onlyvia Discharging Mode double power, the first power standby UPS converter120 and the second power converter 140 Fourth Backup mode, STANDBY DC/ACBattery only via Discharging Mode single power the first power converter120 and the second power converter 140 Fifth Energy storage AC/DC orAC/DC or AC2 Charging or Mode mode, double DC/AC DC/AC discharging orpower nothing Sixth Energy storage AC/DC or AC/DC or AC2 Charging orMode mode double DC/AC DC/AC discharging or power with UPS nothingability Seventh Backup mode AC/DC or DC/AC AC1 and/or Charge or Mode andEnergy DC/AC Battery discharge or Storage Together nothing EighthPartial Energy AC/DC or DC/AC AC1 and/or Charge or Mode storage modeDC/AC BATTERY discharge or with a single nothing power UPS (option 1)Ninth Partial Energy STANDBY DC/AC or AC2 and/or Charge or Mode storagemode AC/DC or BATTERY discharge or with a single STANDBY nothing powerUPS (option 2) Tenth Energy path only STANDBY DC/AC or AC2 and/or Chargeor Mode to AC 2 AC/DC or BATTERY discharge or STANDBY nothing

For example, and without limiting the generality of the foregoing, themodes in Table 1 are as follows:

Normal Mode (First Mode)—AC electricity input to the UPS 100 is withinspecified tolerances of the UPS 100; the battery 130 is charged orcharging; and the load 150 is within a specified rating of the UPS 100.In normal mode, UPS 100 may operate as an on-line UPS. In this mode, theUPS 100 receives input AC power at the first terminal 110 and at thesecond terminal 160.

It is understood that all discussions of AC input refer to an AC inputwithin predetermined tolerances for a given UPS device 100. By way ofexample, the UPS device 100 may be rated to receive up to 400 V AC ±10%as a single phase AC input. By way of another example, the UPS device100 may be rated to receive up to 400 V AC×3 as a three phase UPS device±10%. In the above examples, the tolerance of ±10% is also given by wayof example. In some UPS devices 100, other tolerances may be found,e.g., ±15%, ±8%, +10% −7%, and so forth. If the grid is no longer able,for whatever reason, to provide the full power rating and its tolerance(e.g. if the UPS device 100 is rated to receive 400 V AC ±10%, and thegrid is only able to provide 350 V AC), the input power is derated(e.g., 200V at 10 A), and the UPS continues to operate accordingly.Optionally, the UPS device 100 may enter stored energy mode, and notprovide an output to the load if the grid is no longer able to providethe full rating However, if the grid exceeds the full power rating e.g.if the UPS device 100 is rated to receive 400 V AC ±10%, and the grid isnow providing 450 V AC), the UPS device 100 may shut down.

Additionally, the battery 130 remains charged (or is recharging). Thatis to say, the UPS 100 is providing AC power to the load 150, as willnow be explained. Switches SW1 and SW1.1 may both be closed, and so,power may be provided to the first power converter 120, which convertsthe AC input power to DC power inputted to second power converter 140and (optionally) inputted to battery 130. The second power converter 140may convert the DC power to AC output power inputted to the load 150.

Bypass Mode (Second Mode)—the current path through the UPS 100 into theload 150 does not go through the first power converter 120 and thesecond power converter 140. Rather, the first power converter 120 andthe second power converter 140 are bypassed, and the current path to theload 150 is via the second AC terminal 160 via switch SW2 and CR2. Inbypass mode, switch SW1 may be closed and SW1.1 closed, providing acurrent path into not including CR1. Switch SW2 may be closed and SW2.1opened, providing a current path power via CR2. In this case, shouldthere be a power failure, CR2 may disconnect and the UPS may convertpower stored by battery 130 in order to provide power to the load 150.Switch SW3 may be closed, so that power from AC1 and AC2 may bypass thefirst power converter 120 and the second power converter 140, and reachthe load 150. The first power converter 120 and the second powerconverter 140 may both function to charge the battery 130 using powerfrom the first terminal 110 and second terminal 160. The UPS functionsas a standby UPS, only switching into providing power from the battery130 to the load 150 via circuit 140 if based on a loss of AC power atthe first terminal 110.

In Backup mode, double power, standby UPS (Third Mode)—switch SW3 may beclosed, and at least switches SW1 and SW2 are open. Thus, power may beprovided to the load 150 via both the first power converter 120 and thesecond power converter 140 from the battery 130. Since the battery 130may be providing power to the load 150, there might not be need for CR1and CR2 to enable switching to the UPS 100 to rapidly provide power tothe load 150.

In Backup mode, single power (Fourth Mode)—switches SW1, SW1.1, SW2,SW2.1, and SW3 are all open. Power is provided to the load 150 from thebattery 130 via the second power converter 140.

Energy Storage Mode, double power (Fifth Mode)—AC electricity input tothe UPS 100 is disconnected, not within specified tolerances of the UPS100 and the battery 130 is outputting power (as will be detailed below);and the load 150 is within a specified rating of the UPS 100 itself. InStored Energy mode, power from stored energy, is provided to the grid,as will now be explained. Switches SW1, SW1.1, SW2, and SW2.1 may all beclosed. CR1 and CR2 may both be off. Power is provided to the load 150from the second terminal 160, via switches SW2 and SW2.1. The battery130 may provide power to the first power converter 120, which in turnprovides an output via switches SW1 and SW1.1 to the grid.

In the Energy Storage mode, double power with UPS ability (SixthMode)—SW1 may be closed and SW1.1 opened, providing a current path toCR1. Switch SW2 is closed and SW2.1 opened, providing a current path toCR2. SW2.1 is open, so that power can flow bidirectionally from thesecond circuit 140 and second terminal 160. Since CR1 and CR2 are bothin the current path, a rapid activation of the UPS by providing powerfrom the battery 130 to the load 150 may be possible, if necessary.Power may flow from the first power converter 120 to the first terminal110. Since switch SW1.1 is open, switch SW3 may be open as well, whichmay prevent power from flowing from the second terminal 160 into firstterminal 110.

In Backup mode and Energy Storage Together (Seventh Mode)—SW1 and SW1.1are closed, SW2, SW2.1, and SW3 are open, so that if there is a failureof AC2, AC1 continues to provide power. Power may then be provided tothe load via the second circuit 140, and to the AC1 grid via the firstpower converter 120.

In the Partial Stored Energy single power mode with a single power UPS(option 1) (Eighth Mode)—switches SW1 and SW1.1 are both closed.Accordingly, the first power converter 120 is providing power to thegrid from the battery 130. The second circuit 140 is providing powerfrom the battery 130 to the load 150. Since the battery 130 is providingpower to the load 150, switches SW2, SW2.1, SW3 and the two SCRs CR1 andCR2 may be open/off. The switch states of partial Stored Energy singlepower mode, (option 1) is similar to both the backup mode and EnergyStorage Together and Normal mode. However, in Normal mode, the firstpower converter 120 is operating in a unidirectional manner, convertingAC power to DC power, and providing the DC power to the battery 130 atterminal T1. In the backup mode and Energy Storage Together, the firstpower converter 120 and the battery 130 are not bypassed, and there isstorage of energy in the battery 130. In the partial Stored Energysingle power mode, (option 1), the first power converter 120 and thebattery 130 are bypassed, and the first power converter 120 operatesbidirectionally, so power may be provided to AC1.

In the Partial Stored Energy mode with a single power UPS (option 2)(Ninth Mode)—switches SW1 and SW1.1 are both open and switches SW2 andSW2.1 are both closed. The second circuit 140 may providing power fromthe battery 130 to the load 150 and AC2.

In the Energy path only to AC 2 mode (Tenth Mode)—the switches SW1,SW1.1, CR1, SW2.1 and SW3 are open/off, and switches SW2 and CR2 areclosed/on. In this mode an energy path is provided from AC2 to the load150 through CR2.

Reference is made to FIG. 1A which is a flow chart providing an exampleof operation of the UPS 100 with the UI 180. A user may interact withthe UI 180 to select one of the modes described above (for example,“normal mode”) as a desired mode of operation of the UPS device 100(step 191). The controller 170 receives the user selection from the UI180, and in the presence of the lower level controllers (for example,172, 174, 176) (step 193), sends appropriate commands (for example, overa communications bus) to the lower level controllers as to how thevarious switches, SCRs, and power conversion circuits are to beconfigured (step 195, optional). In the absence of the lower levelcontrollers, the controller 170 may communicate directly with theswitches, SCRs, and power conversion circuits to be configured (step197). For example, in normal mode, the controller 170 sends commands forSW1, SW1.1, and SW2 to be closed (or, in the absence of lower levelcontrollers, directly causes SW1, SW1.1, and SW2 to be closed), and forCR1, SW2.1, CR2, and SW3 to be open (OFF), for first power converter 120to convert AC power to DC power, and for second circuit 140 to convertDC power to AC power. A similar process may be followed to appropriatelyconfigure the UPS for other modes of operation, as per user selectionvia the UI 180.

Reference is now made to FIG. 2 , which is a flow chart 200 of a methodfor implementing the UPS of FIG. 1 . In step 210 a first alternatingcurrent (AC) is input into an uninterruptible power source (UPS), theUPS being operative to input AC power to a first circuit, e.g., thefirst circuit having a DC terminal connected to a battery. In step 220,AC current is input into a second AC input, the second AC inputoperative to input power to the load 150, e.g., SW2 and SW2.1 areclosed, and current flows to the load 150 via terminal 190. the In step230 AC current is input into the second AC input, the second AC inputbeing operative to input power to the load 150, e.g., SW2 and SW2.1 areclosed, and current flows to the load 150 via terminal 190, as describedabove with reference to step 220. Further, the first circuit may providepower to the battery 130 when SW1 and SW1.1 are closed providing powerto the first power converter 120, which converts AC electricity receivedon the AC terminal from the first AC electricity input to DC electricityon the DC terminal. The second circuit has an output to the load 150. Instep 240, SW3 is closed, a conduction path is provided from the first ACinput to the load 150, said conduction path not via the first circuit(e.g., bypassing the first circuit may be bypassed via SW3). In step 250switches disposed in current paths in the UPS may be controlled by acontroller. In step 260 at least two SCRs may be provided. Morespecifically, a first SCR is provided between the first AC input and theconduction path. A second SCR is provided, which is disposed between thesecond AC input and the load 150. In step 270 a plurality of switchesmay be provided, wherein the UPS provides power at least to an AC gridand the load 150 as a result of switching states of the plurality ofswitches.

Reference is now made to FIG. 3 , which is a flow chart 300 of a methodfor controlling modes of operation of the UPS of FIG. 1 . An input isreceived at the UI 180, the input including at least a desired mode ofoperation selected by a user of the UPS 100 (step 310). The desired modeof operation may be provided by the user providing direct input to theUI 180, over a wired or wireless communication interface, or the inputis provided by a device which itself has computing or processingcapability. For example, the user may either press a button orcombination of buttons directly on the UPS 100 in order to configure thedesired mode of operation of the UPS 100. In an alternative method, theuser may (in step 310) configure the desired mode of operation of theUPS 100 using a touch screen on an outer case of the UPS 100. In stillanother method of inputting the desired mode of operation, the user mayinterface with an application on a mobile computer (e.g., a cell phoneor tablet computer), which then will wirelessly (e.g, via Bluetooth orWiFi) send a configuration command to the UPS 100. Alternatively oradditionally, a desk top computer may be used as an interface by whichthe user may select mode of operation of the UPS 100. The desk topcomputer may (in step 310), via a wireless or wired connection, e.g., anEthernet connection (to an Ethernet terminal not depicted in FIG. 1 ,for example, of controller 170), transmit the configuration command tothe UPS 100.

In another example, a computer may comprise hardware, software, or acombination thereof, for monitoring at least one UPS. The computer mayselect a mode of operation based on internal logic by which it operatesin order to select a mode of operation of the UPS. For example, uponactivation, the computer may select Normal mode of operation. After, forexample, 48 hours during which the UPS does not provide power to theload, the computer may then opt to select to operate the UPS in EnergyStorage mode, double power. Thus, after a certain level of stability isindicated in the system, for example, the computer may be programmed toallow the UPS to provide power to the grid. For example, when the gridis not providing power to the first or the second AC terminal, the UPSmay use the first of second power converter to provide power to thegrid.

The received desired mode of operation may be transmitted from the userinterface 180 to the high level controller 170 of the UPS 100 (step320). Switch states, as described above in the discussion of FIG. 1 ,for the desired mode of operation are determined by the high levelcontroller 170 at step 340 (e.g., by retrieving the states from a lookup table stored in computer memory). The high level controller 170 ofthe UPS 100 may optionally transmit the determined switch states to thelower-level controllers 172, 174, 176 (step 330). The lower-levelcontrollers 172, 174, 176 and/or the high level controller 170 may thenconfigure the switches in the UPS according to the determined switchstates (step 350).

Reference is now made to FIG. 4 , which shows a variation of the UPS 400constructed in accordance with the present disclosure. The UPS 400 ofFIG. 4 in general operates with the same or similar way as the UPS 100of FIG. 1 , and may have similar operational states as the operationalstates of UPS 100 of FIG. 1 described above. FIG. 4 shows a topology inwhich, for example, the first input terminal 110 may be configured anddesigned to receive a first AC electricity input from the grid. Thesecond terminal 160 may be configured and designed to receive a secondAC electricity input from an alternative supply of AC electricity, forexample, a gasoline, propane, natural gas, or diesel generator, windturbine, or inverter connected to a photovoltaic power source. It may bethe case when there are two distinct sources of AC electricity that thetwo sources might not be in synchrony with one another. Morespecifically, wave forms from the alternative supply of AC electricity,should match (for example in voltage, phase and/or frequency) thewaveforms of AC electricity from the grid. That is, the AC electricityreceived at the second terminal 160 should match the AC electricityreceived at the first terminal 110 in voltage, frequency, phase, and (incase of multiple phases) phase sequence. The UPS may isolate onegenerator of AC electricity (e.g., form a generator) from the secondsource of AC electricity (e.g., grid)) until it is within apredetermined tolerance of the phase, frequency, and amplitude of thesecond source of AC electricity. Isolation of a source of AC electricitymay be achieved in the system described herein, by opening of switchesSW1, SW1.1, SW2, and/or SW2.1.

Reference is now made to FIG. 5 which is a flow chart of operation ofthe UPS device 400 as a switch. In such a case as described in FIG. 4 ,the controller 170 may operate the UPS device 400 of FIG. 4 as a switchin order to seamlessly transfer from the first source of AC electricityto the second source of AC electricity (step 510). For example, in theevent of a power outage, the first source of AC electricity received atthe first terminal 110 might no longer provide an input AC power. Basedon detecting a decrease in or no input AC power at first terminal 110,the controller 170 may open SW3 to disconnect AC1 from the load 150, andclose SW2 and SW2.1 to connect AC2 to the load 150, thus maintainingflow of AC electricity to the load (step 520). The controller 170 maythen synchronize the phase of power provided from the battery 130 to theload 150 via the second circuit 140 to the power received at secondterminal 160 from the alternative supply of AC electricity (step 530).

Reference is now made to FIG. 6 , which is an example block diagram ofan architecture of a controller 600 for a UPS such as UPS 100 or 400.The controller 600 may comprise one or more processors, such asprocessor 601, providing an execution platform for executingmachine-readable instructions such as software. One of the processors601 may be a special purpose processor operative for executing theoperations of the UPS controller (e.g., as in 170, 172, 174, or 176).

Commands and data from the processor 601 may be communicated over acommunication bus 602. The controller 600 may include a main memory 603,such as a Random Access Memory (RAM) 604, where machine readableinstructions may reside during runtime, and a secondary memory 605. Thesecondary memory 605 may include, for example, a hard disk drive 607and/or a removable storage drive 608 (which may be not generallyaccessible on a regular basis, but possibly accessible by servicepersonnel or installers, etc.), such as a floppy diskette drive, amagnetic tape drive, a compact disk drive, a flash drive, etc., or anonvolatile memory where a copy of the machine readable instructions orsoftware may be stored. The secondary memory 605 may also include ROM(read only memory), EPROM (erasable, programmable ROM), EEPROM(electrically erasable, programmable ROM). In addition to software, datarelevant to the operation of the UPS 100, 400 as described herein above,or other similar data may be stored in the main memory 603 or thesecondary memory 605. The removable storage drive 608 may read from orwrite to a removable storage unit 609.

A user may interface with the UPS controller 600 via the user interface(as described above with reference to FIG. 1A which includes inputdevices 611, such as a touch screen, a keyboard, a mouse, a stylus, andthe like, as well as interfaces for input via the wireless interface, inorder to provide user input data or other commands. A display adaptor616 interfaces with the communication bus 602 and a display 617 andreceives display data from the processor 601 and converts the displaydata into display commands for the display 617.

A network interface 619 is provided for communicating with other systemsand devices via a network. The network interface 619 typically includesa wireless interface for communicating with wireless devices in thewireless community. A wired network interface (an Ethernet interface, byway of example) may be present as well. The controller 600 may alsocomprise other interfaces, including, but not limited to Bluetooth orHDMI.

It is appreciated that one or more of the above-described components ofthe controller 600 may not be included, or other components may beadded. The controller 600 shown in FIG. 6 is provided as an example of apossible platform that may be used, and other appropriate types ofplatforms may be used as alternative platforms. One or more of the stepsdescribed above may be implemented as instructions embedded on acomputer readable medium and executed on the controller 600. The stepsmay be embodied by a computer program, which may exist in a variety offorms both active and inactive. For example, they may exist as softwareprogram(s) comprised of program instructions in source code, objectcode, executable code or other formats for performing some of the steps.Any of the above may be embodied on a computer readable medium, whichinclude storage devices and signals, in compressed or uncompressed form.Examples of suitable computer readable storage devices includeconventional computer system RAM (random access memory), ROM (read onlymemory), EPROM (erasable, programmable ROM), EEPROM (electricallyerasable, programmable ROM), hardware registers (e.g., in an ASIC), ormagnetic or optical disks or tapes. Examples of computer readablesignals, whether modulated using a carrier or not, are signals that acomputer system hosting or running a computer program may be configuredto access, including signals downloaded through the Internet or othernetworks. Concrete examples of the foregoing include distribution of theprograms on a CD ROM, on a flash drive, or via Internet download.Computer readable medium may further include further include any numberof the above mentioned device used in combination, either in a singlecomputer device or multiple computer devices networked together (e.g.,cloud based storage).

The skilled person will appreciate that inventive aspects disclosedherein include an apparatus or a system as in any of the followingclauses:

Clause 1. An apparatus including an uninterruptible power supply (UPS)including a load terminal, a first alternating current (AC) terminalconfigured to provided AC power to a first power converter circuit, asecond AC terminal, configured to provided power to a load terminal, thefirst power converter circuit connected to a battery and to a secondpower converter circuit, the second power converter circuit connected tothe load terminal, a first switch circuit disposed between the first ACterminal and the first power converter circuit, a second switch circuitdisposed between the second AC terminal and the load terminal, and oneor more controllers configured to control the first switch circuit, thesecond switch circuit, the first power converter circuit, and the secondpower converter circuit, wherein the one or more controllers areconfigured to operate the first switch circuit, the second switchcircuit, the first power converter circuit, and the second powerconverter circuit in a plurality of operating modes.

Clause 2. The apparatus according to clause 1, wherein the first powerconverter circuit is configured to convert direct current (DC) power toalternating current (AC) power.

Clause 3. The apparatus according to either of clauses 1 and 2, whereinthe first power converter circuit is configured to convert AC power toDC power.

Clause 4. The apparatus according to any of clauses 1-3, wherein thesecond power converter circuit is configured to convert AC power to DCpower.

Clause 5. The apparatus according to any of clauses 1-4, wherein thesecond power converter circuit is configured to convert DC power to ACpower.

Clause 6. The apparatus according to any of clauses 1-5, wherein thefirst switch circuit includes a first switch, a second switch, and afirst SCR, wherein the first switch and second switch are disposed inseries between the first AC terminal and the first power converter, andwherein the first SCR is disposed in parallel to the second switch.

Clause 7. The apparatus according any of clauses 1-6, wherein the secondswitch circuit includes a third switch, a fourth switch, and a secondSCR, wherein the third switch and the fourth switch are disposed betweenthe second AC terminal and the load terminal, and wherein the second SCRis disposed in parallel to the fourth switch.

Clause 8. The apparatus according to any of clauses 1-7, furtherincluding a fifth switch connected between the first switch circuit andthe load terminal.

Clause 9. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a first mode, wherein when in the first mode,the one or more controllers are configured to set the first switch in aclosed state, the second switch in a closed state, the first SCR in anon-operative state, the third switch in a closed state, the fourthswitch in an open state, the second SCR in a non-operative state, andthe fifth switch in an open state.

Clause 10. The apparatus according to clause 9, wherein the one or morecontrollers are configured, when operating in the first mode, to operatethe first power converter circuit to convert AC power received from thefirst AC terminal to DC power.

Clause 11. The apparatus according to clause 10, wherein the one or morecontrollers are configured, when operating in the first mode, to operatethe second power converter to convert the DC power to output AC power,and provide the output AC power to the load.

Clause 12. The apparatus according to clause 10 or clause 11, whereinthe one or more controllers are configured, when operating in the firstmode, to operate the second power converter to convert DC power drawnfrom the battery to output AC power, and provide the output AC power tothe load.

Clause 13. The apparatus according to clause 10 or clause 11, whereinthe one or more controllers are configured, when operating in the firstmode, to charge the battery with the DC power.

Clause 14. The apparatus according to clause 10 or clause 11, whereinthe one or more controllers are configured, when operating in the firstmode, to discharge the battery.

Clause 15. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a second mode, to operatethe first power converter circuit to convert AC power received from thefirst AC terminal to DC power.

Clause 16. The apparatus according to clause 15 wherein the one or morecontrollers are configured, when operating in the second mode, tooperate the second power converter to be in standby mode.

Clause 17. The apparatus according to clause 15 or clause 16, whereinthe one or more controllers are configured, when operating in the secondmode, to charge the battery with the DC power.

Clause 18. The apparatus according to any one of clauses 15-17, whereinthe one or more controllers are configured, when operating in the secondmode, to set the third switch in a closed state to provide AC power fromthe second AC terminal to the load.

Clause 19. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a third mode, to operatethe first power converter to convert DC power received from the batteryto AC power.

Clause 20. The apparatus according to clause 19, wherein the one or morecontrollers are configured, when operating in the third mode, to operatethe second power converter to convert DC power received from the batteryto AC power.

Clause 21. The apparatus according to clause 19 or clause 20, whereinthe one or more controllers are configured, when operating in the thirdmode, to discharge the battery.

Clause 22. The apparatus according to any of clauses 19-21, wherein theone or more controllers are configured, when operating in the thirdmode, to operate the first power converter to convert the DC power tooutput AC power, and provide the output AC power to the load.

Clause 23. The apparatus according to any of clauses 19-22, wherein theone or more controllers are configured, when operating in the thirdmode, to operate the second power converter to convert the DC power tooutput AC power, and provide the output AC power to the load.

Clause 24. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a fourth mode, to operatethe first power converter in standby mode.

Clause 25. The apparatus according to clause 24, wherein the one or morecontrollers are configured, when operating in the fourth mode, tooperate the second power converter to convert DC power received from thebattery to AC power.

Clause 26. The apparatus according to clause 24 or clause 25, whereinthe one or more controllers are configured, when operating in the fourthmode, to discharge the battery.

Clause 27. The apparatus according to clause 24-26, wherein the one ormore controllers are configured, when operating in the fourth mode, tooperate the second power converter to convert the DC power to output ACpower, and to provide the output AC power to the load.

Clause 28. The apparatus according to clause 24-27, wherein the one ormore controllers are configured, when operating in the fourth mode, tooperate the second power converter to convert the DC power to output ACpower, and to provide the output AC power to the load.

Clause 29. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a fifth mode or sixthmode, to operate the first power converter to convert DC power receivedfrom the battery to AC power.

Clause 30. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in the fifth mode or thesixth mode, to operate the first power converter to convert AC powerreceived from the first AC terminal to DC power.

Clause 31. The apparatus according to clause 29 or clause 30, whereinthe one or more controllers are configured, when operating in the fifthmode or the sixth mode, to operate the second power converter to convertDC power received from the battery to AC power.

Clause 32. The apparatus according to clause 29 or clause 30, whereinthe one or more controllers are configured, when operating in the fifthmode or the sixth mode, to operate the second power converter to convertAC power received from the second AC terminal to DC power provided tothe battery.

Clause 33. The apparatus according to any of clauses 30-32, wherein theone or more controllers are configured, when operating in the fifth modeor the sixth mode, to discharge the battery.

Clause 34. The apparatus according to any of clauses 30-clause 32,wherein the one or more controllers are configured, when operating inthe fifth mode or the sixth mode, to charge the battery.

Clause 35. The apparatus according to any one of clauses 30-34, whereinthe one or more controllers are configured, when operating in the sixthmode, to set the third switch in a closed state to provide the AC powerto the load.

Clause 36. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a seventh mode, to operatethe first power converter to convert DC power received from the batteryto AC power.

Clause 37. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a seventh mode, to operatethe first power converter to convert AC power received from the first ACterminal to DC power.

Clause 38. The apparatus according to clause 36 or clause 37, whereinthe one or more controllers are configured, when operating in theseventh mode, to operate the second power converter to convert DC powerreceived from the battery to AC power.

Clause 39. The apparatus according to any of clauses 36-38, wherein theone or more controllers are configured t, when operating in the seventhmode, to discharge the battery.

Clause 40. The apparatus according to any of clauses 36-38, wherein theone or more controllers are configured, when operating in the seventhmode, to charge the battery with DC power.

Clause 41. The apparatus according to any of clauses 36-40 wherein, theone or more controllers are configured, when operating in the seventhmode, to operate the first power converter to convert DC power drawnfrom the battery to output AC power, and to provide the output AC powerto the load.

Clause 42. The apparatus according to any of clauses 36-40 wherein, theone or more controllers are configured, when operating in the seventhmode, to route power from the first AC terminal to be provided to theload.

Clause 43. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a eighth mode, to operatethe first power converter to convert AC power received from the firstterminal to DC power.

Clause 44. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in the eighth mode, tooperate the first power converter to convert DC power drawn from thebattery to AC power.

Clause 45. The apparatus according to clause 43 or 44, wherein the oneor more controllers are configured, when operating in the eighth mode,to operate the second power converter to convert DC power drawn from thebattery to AC power.

Clause 46. The apparatus according to any of clauses 43-45, wherein theone or more controllers are configured, when operating in the eighthmode, to discharge the battery.

Clause 47. The apparatus according to any of clauses 43-45, wherein theone or more controllers are configured, when operating in the eighthmode, to charge the battery with DC power.

Clause 48. The apparatus according to any of clauses 43-48, wherein theone or more controllers are configured, when operating in the eighthmode, to operate the second power converter to convert the DC power tooutput AC power, and to provide the output AC power to the load.

Clause 49. The apparatus according to any of clauses 43-48, wherein theone or more controllers are configured, when operating in the eighthmode, to provide power received from the first AC terminal to the load.

Clause 50. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in a ninth mode, to operatethe first power converter in standby mode.

Clause 51. The apparatus according to clause 50, wherein the one or morecontrollers are configured, when operating in the ninth mode, to operatethe second power converter in standby mode.

Clause 52. The apparatus according to either clause 50 or 51, whereinthe one or more controllers are configured, when operating in the ninthmode, to operate the second power converter to convert DC power receivedfrom the battery to AC power and provide the AC power to the load.

Clause 53. The apparatus according to either clause 50 or 51, whereinthe one or more controllers are configured, when operating in the ninthmode, to operate the second power converter to convert AC power receivedfrom the second AC terminal to DC power.

Clause 54. The apparatus according to any of clauses 50-53, wherein theone or more controllers are configured, when operating in the ninthmode, to provide power received from the second AC terminal to the load.

Clause 55. The apparatus according to any of clauses 50-53, wherein theone or more controllers are configured, when operating in the ninthmode, to operate the second power converter to convert DC power drawnfrom the battery to output AC power, and provide the output AC power tothe load.

Clause 56. The apparatus according to clause 8, wherein the one or morecontrollers are configured, when operating in tenth mode, to operate thefirst power converter in standby mode.

Clause 57. The apparatus according to clause 56, wherein the one or morecontrollers are configured, when operating in the tenth mode, to operatethe second power converter in standby mode.

Clause 58. The apparatus according to clause 56, wherein the one or morecontrollers are configured, when operating in the tenth mode, to operatethe second power converter in standby mode.

Clause 59. The apparatus according to clause 56, wherein the one or morecontrollers are configured, when operating in the tenth mode, to operatethe second power converter to convert DC power drawn from the battery tooutput AC power.

Clause 60. The apparatus any of clauses 56-59, wherein the one or morecontrollers are configured, when operating in the tenth mode, to operatethe second power converter to convert the DC power to output AC power,and provide the output AC power to the load.

Clause 61. The apparatus according to any of clauses 56-59, wherein theone or more controllers are configured, when operating in the tenthmode, to operate the second power converter to convert the AC powerreceived at the second AC terminal, to DC power.

Clause 62. The apparatus according to clause 61, wherein the one or morecontrollers are configured, when operating in the tenth mode, to operatethe second power converter to convert the AC power received at thesecond AC terminal to DC power, and provide the DC power to the battery.

Clause 63. The apparatus according to any of clauses 56-62, wherein theone or more controllers are configured, when operating in the tenthmode, to discharge the battery.

Clause 64. The apparatus according to any of clauses 56-62, wherein theone or more controllers are configured, when operating in the tenthmode, to charge the battery.

Clause 65. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a second mode, wherein the one or morecontrollers are configured, when operating in the second mode, to setthe first switch in a closed state, the second switch in a closed state,the first SCR in a non-operative state, the third switch in a closedstate, the fourth switch in an open state, the second SCR in anoperative state, and the fifth switch in an open state.

Clause 66. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a third mode, wherein the one or morecontrollers are configured, when operating in the third mode, to set thefirst switch in an open state, the second switch in an open state, thefirst SCR in a non-operative state, the third switch in an open state,the fourth switch in an open state, the second SCR in an open state, andthe fifth switch in a closed state.

Clause 67. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a fourth mode, wherein the one or morecontrollers are configured, when operating in the fourth mode, to setthe first switch in an open state, the second switch in an open state,the first SCR in a non-operative state, the third switch in an openstate, the fourth switch in an open state, the second SCR in anon-operative state, and the fifth switch in an open state.

Clause 68. The apparatus according to clause 8, wherein the plurality ofoperating modes includes fifth mode, wherein the one or more controllersare configured, when operating in the fifth mode, to set the firstswitch in a closed state, the second switch in a closed state, the firstSCR in a non-operative state, the third switch in a closed state, thefourth switch in a closed state, the second SCR in a non-operativestate, and the fifth switch in an open state.

Clause 69. The apparatus according to clause 8, wherein the plurality ofoperating modes includes sixth mode, wherein the one or more controllersare configured, when operating in the sixth mode, to set the firstswitch in a closed state, the second switch in an open state, the firstSCR in an operative state, the third switch in a closed state, thefourth switch in an open state, the second SCR in an operative state,and the fifth switch in a closed state.

Clause 70. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a seventh mode, wherein the one or morecontrollers are configured, when operating in the seventh mode, to setthe first switch in a closed state, the second switch in a closed state,the first SCR in a non-operative state, the third switch in an openstate, the fourth switch in an open state, the second SCR in anon-operative state, and the fifth switch in an open state.

Clause 71. The apparatus according to clause 8, wherein the plurality ofoperating modes includes as eighth mode, wherein the one or morecontrollers are configured, when operating in the eighth mode, to setthe first switch in a closed state, the second switch in a closed state,the first SCR in a non-operative state, the third switch in a closedstate, the fourth switch in an open state, the second SCR in anon-operative state, and the fifth switch in an open state.

Clause 72. The apparatus according to clause 8, wherein the plurality ofoperating modes includes a ninth mode, wherein the one or morecontrollers are configured, when operating in the ninth mode, to set thefirst switch in an open state, the second switch in an open state, thefirst SCR in a non-operative state, the third switch in a closed state,the fourth switch in an closed state, the second SCR in a non-operativestate, and the fifth switch in an open state.

Clause 73. The apparatus according to clause 8, wherein the plurality ofoperating modes includes an tenth mode, wherein the one or morecontrollers are configured, when operating in the tenth mode, to set thefirst switch in an open state, the second switch in an open state, thefirst SCR in a non-operative state, the third switch in a closed state,the fourth switch in an open state, the second SCR in an operativestate, and the fifth switch in an open state.

Clause 74 The apparatus according to any of clauses 1-73, wherein theone or more controllers are configured to operate the first switchcircuit, the second switch circuit, the first power converter, and thesecond power converter to receive a power from the first AC terminal andthe second AC terminal and provide the power to the load.

Clause 75. The apparatus according to any of clauses 1-74, wherein theone or more controllers are configured to operate the first switchcircuit, the second switch circuit, the first power converter, and thesecond power converter to receive a power from the battery and providethe power to the first AC terminal or the second AC terminal.

Clause 76. A method including inputting a first alternating current (AC)into an uninterruptible power source (UPS) at a first AC terminal, theUPS operative to input AC power into a first power converter, inputtingAC current into the UPS at a second AC terminal, the second AC terminaloperative to input power to a load, wherein the first power converterhaving an output to a battery and a second power converter, the secondpower converter having an output to the load, providing a secondconduction path from the first AC terminal to the load, the secondconduction path not via the first power converter, controlling switchesdisposed in current paths in the UPS by a controller, providing at leasttwo silicon controlled rectifiers (SCRs), a first SCR between the firstAC terminal and the second conduction path, and a second SCR, disposedbetween the second AC terminal and the load, and providing a pluralityof switches, wherein the UPS provides power at least to an AC grid andthe load.

Clause 77. The method according to clause 76, wherein the first powerconverter includes a first inverter circuit.

Clause 78. The method according to clause 76 or 77, wherein the firstpower converter includes a first AC-to-DC converter circuit.

Clause 79. The method according to any of clauses 76-78, wherein thesecond power converter includes a second inverter circuit.

Clause 80. The method according to any of clauses 76-79, wherein thesecond power converter includes a second AC-to-DC converter circuit.

Clause 81. The method according to any of clauses 76-80, wherein a firstswitch of the plurality of switches is disposed between the first ACterminal to the load and the first SCR.

Clause 82. The method according to any of clauses 76-81, wherein asecond switch of the plurality of switches is disposed in parallel tothe first SCR.

Clause 83. The method according to any of clauses 76-82, wherein a thirdswitch of the plurality of switches is disposed along the secondconduction path.

Clause 84. The method according to any of clauses 76-83, wherein afourth switch of the plurality of switches is disposed between thesecond AC terminal and the second SCR.

Clause 85. The method according to any of clauses 76-84, wherein a fifthswitch of the plurality of switches is disposed in parallel to thesecond SCR.

Clause 86. The method according to any of clauses 76-85, comprisingoperating the UPS as a bypass mode UPS.

Clause 87. The method according to any of clauses 76-86, comprisingoperating the UPS as a backup mode UPS.

Clause 88. The method according to any of clauses 76-87, comprisingoperating the UPS as an Energy Storage System mode UPS.

Clause 89. The method according to any of clauses 76-88, comprisingreceiving, by the UPS, power from both the first AC terminal and thesecond AC terminal and outputting the power via the UPS to the load.

Clause 90. An apparatus including an uninterruptible power supply (UPS)including a first alternating current (AC) terminal, which inputs ACpower to a first circuit, a second AC terminal, which inputs power to aload, the first circuit having an output to a battery and a secondcircuit, the second circuit having an output to the load, an additionalconduction path from the first AC terminal to the load, the additionalconduction path not via the first circuit, a controller, operative tocontrol switches disposed in current paths in the UPS, at least twosilicon controlled rectifiers (SCRs), a first SCR between the first ACterminal and the additional conduction path, and a second SCR, disposedbetween the second AC terminal and the load, and a plurality ofswitches, wherein the UPS provides power at least to an AC grid and theload as a result of switching states of the plurality of switches.

Clause 91. The apparatus according to clause 90, wherein the firstcircuit includes a first inverter circuit.

Clause 92. The apparatus according to either clause 90 or 91, whereinthe first circuit includes a first rectifier circuit.

Clause 93. The apparatus according to any of clauses 90-92, wherein thesecond circuit includes a second inverter circuit.

Clause 94. The apparatus according to any of clauses 90-93, wherein thesecond circuit includes a second rectifier circuit.

Clause 95. The apparatus according to any of clauses 90-94, wherein afirst switch of the plurality of switches is disposed between the firstAC terminal to the load and the first SCR.

Clause 96. The apparatus according to any of clauses 90-95, wherein asecond switch of the plurality of switches is disposed in parallel tothe first SCR.

Clause 97. The apparatus according to any of clauses 90-96, wherein athird switch of the plurality of switches is disposed along theadditional conduction path.

Clause 98. The apparatus according to any of clauses 90-97, wherein afourth switch of the plurality of switches is disposed between thesecond AC terminal and the second SCR.

Clause 99. The apparatus according to any of clauses 90-98, wherein afifth switch of the plurality of switches is disposed in parallel to thesecond SCR.

Clause 100. The apparatus according to any of clauses 90-99, wherein theUPS is operating as a bypass mode UPS.

Clause 101. The apparatus according to any of clauses 90-100, whereinthe UPS is operating as a backup mode UPS.

Clause 102. The apparatus according to any of clauses 90-101, whereinthe UPS is operating as an Energy Storage System mode UPS.

Clause 103. The apparatus according to any of clauses 90-102, whereinthe UPS outputs power from the both first AC terminal and the second ACterminal to the load.

Clause 104. A method including receiving an input of a mode of operationof a plurality of modes of operation of an uninterruptible power source(UPS) at a user interface, transmitting the received mode of operationto a high level UPS controller from the user interface, transmittingappropriate switch states from the high level UPS controller to one ormore low level UPS controllers, configuring at least one switch in theUPS according to the transmitted appropriate switch states, wherein theappropriate switch states are set so as to configure the USP to operatein the mode of operation received at the user interface.

Clause 105. The method according to clause 104, wherein the UPS includesa first terminal connected to an electricity grid, a first switchdisposed between the first terminal and a first pair of siliconcontrolled rectifiers (SCRs), a second switch parallel to the first pairof SCRs, a third switch, between the first pair of SCRs and the secondswitch, and a first bidirectional inverter, a battery, a secondbidirectional inverter, a second terminal connected to an electricitygrid, a fourth switch disposed between the second terminal and a secondpair of SCRs, a fifth switch parallel to the second pair of SCRs.

Clause 106. The method according to clause 105, wherein the plurality ofmodes of operation include a normal mode of operation in which the firstswitch, the second switch and the third switch are closed, and whereinthe normal mode of operation includes the UPS functioning as an on-lineUPS.

Clause 107. The method according to any of clauses 105-106, wherein theplurality of modes of operation include a bypass mode of operation inwhich the first switch, the second switch and the third switch areclosed, and a current path is provided into the second pair of SCRs, andwherein the bypass mode of operation includes the UPS functioning as anon-line UPS.

Clause 108. The method according to any of clauses 105-107, wherein theplurality of modes of operation include a backup mode of operation inwhich the fifth switch is closed, and wherein the backup mode ofoperation includes the UPS functioning as a standby UPS.

Clause 109. The method according to any of clauses 105-108, wherein theplurality of modes of operation include a energy storage mode, doublepower mode of operation in which the first switch, the second switch,the third switch, and the fourth switch are closed.

Clause 110. The method according to any of clauses 105-109, wherein theplurality of modes of operation include a energy storage mode, doublepower with UPS ability mode of operation in which the first switch andthe third switch are closed, and a current path is provided into thefirst pair of SCRs and the second pair of SCRs.

Clause 111. The method according to any of clauses 105-110, wherein theplurality of modes of operation include a partial energy storage modewith a single power UPS in which the first switch, the second switch andthe third switch are closed.

Clause 112. An apparatus including a user interface which receives aninput of mode of operation of an uninterruptible power source (UPS), ahigh level UPS controller to which the user interface transmits thereceived mode of operation, a plurality of switches, each switch of theplurality of switches being configurable to be in at least one of twoswitching states, and a plurality of low level controllers which controlthe switching states of each switch of the plurality of switches, based,at least in part, on a transmission of a switch state from the highlevel UPS controller, wherein the switching states of each switch of theplurality of switches are set so as to configure the UPS to operate inthe mode of operation received at the user interface.

Clause 113. The apparatus according to clause 112, wherein the UPSincludes a first terminal connected to an electricity grid, a firstswitch disposed between the first terminal and a first pair of siliconcontrolled rectifiers (SCRs), a second switch parallel to the first pairof SCRs, a third switch, between the first pair of SCRs and the secondswitch, and a first bidirectional inverter, a battery, a secondbidirectional inverter, a second terminal connected to an electricitygrid, a fourth switch disposed between the second terminal and a secondpair of SCRs, a fifth switch parallel to the second pair of SCRs.

Although examples are described above, features and/or steps of thoseexamples may be combined, divided, omitted, rearranged, revised, and/oraugmented in any desired manner. Various alterations, modifications, andimprovements will readily occur to those skilled in the art. Suchalterations, modifications, and improvements are intended to be part ofthis description, though not expressly stated herein, and are intendedto be within the spirit and scope of the disclosure. Accordingly, theforegoing description is by way of example only, and is not limiting.

The invention claimed is:
 1. A method comprising: operating, using acontroller: a first switch of a first switching circuit, a second switchof the first switching circuit, a semiconductor-controlled rectifier(SCR) of the first switching circuit, a first switch of a secondswitching circuit, a second switch of the second switching circuit, anda SCR of the second switching circuit; wherein the first switch of thefirst switching circuit and the second switch of the first switchingcircuit are disposed in series, and wherein the SCR of the firstswitching circuit is disposed in parallel to the second switch of thefirst switching circuit; wherein the first switch of the secondswitching circuit and the second switch of the second switching circuitare disposed in series, and wherein the SCR of the second switchingcircuit is disposed in parallel to the second switch of the secondswitching circuit; and wherein the first switch circuit is disposedbetween a first alternating current (AC) terminal and a firstbidirectional power converter, wherein a battery terminal is disposedbetween the first bidirectional power converter and a secondbidirectional power converter, wherein the second bidirectional powerconverter is directly connected to a load terminal; and wherein thesecond switch circuit is disposed between a second AC terminal and theload terminal.
 2. The method of claim 1, wherein the load terminal, thefirst AC terminal, the second AC terminal, the battery terminal, thefirst switch circuit, the second switch circuit, the first bidirectionalpower converter, and the second bidirectional power converter, areincorporated into an uninterruptible power supply (UPS).
 3. The methodof claim 1, wherein the battery terminal is coupled to at least onebattery.
 4. The method of claim 1, wherein the step of operatingcomprises: operating the first switch of the first switching circuit inan open state; operating the second switch of the first switchingcircuit in an open state; operating the SCR of the first switchingcircuit in a non-operative state; operating the first switch of thesecond switching circuit in an open state; operating the second switchof the second switching circuit in an open state; operating the SCR ofthe second switching circuit in non-operative state; and operating afifth switch in a closed state, wherein the fifth switch is disposedbetween the first switch circuit and the load terminal; and wherein themethod further comprises providing power from the battery terminal tothe load terminal.
 5. The method according to claim 4 wherein thebattery terminal is electrically connected to the load terminal via atleast two power converters.
 6. The method of claim 1, wherein the stepof operating comprises: operating the first switch of the firstswitching circuit in a closed state; operating the second switch of thefirst switching circuit in a closed state; operating the SCR of thefirst switching circuit in a non-operative state; operating the firstswitch of the second switching circuit in a closed state; operating thesecond switch of the second switching circuit in a closed state; andoperating the SCR of the second switching circuit in a non-operativestate; and wherein the method further comprises at least one of: (i)providing power from the second AC terminal to the load terminal; and(ii) providing power from the battery terminal to the first AC terminal.7. The method of claim 1, wherein the step of operating comprises:operating the first switch of the first switching circuit in a closedstate; operating the second switch of the first switching circuit in anopen state; operating the SCR of the first switching circuit in anoperative state; operating the first switch of the second switchingcircuit in a closed state; operating the second switch of the secondswitching circuit in an open state; operating the SCR of the secondswitching circuit in an operative state; and operating a fifth switch ina closed state, wherein the fifth switch is disposed between the firstswitch circuit and the load terminal; and wherein the method furthercomprises at least one of: (i) providing power from the second ACterminal to the load terminal; and (ii) providing power from the batteryterminal to the load terminal.
 8. The method of claim 7, wherein thesecond AC terminal is electrically connected to the load terminal. 9.The method of claim 8, wherein the battery terminal is electricallyconnected to the first AC terminal.
 10. The method of claim 1, whereinthe step of operating comprises: operating the first switch of the firstswitching circuit in a closed state; operating the second switch of thefirst switching circuit in a closed state; operating the SCR of thefirst switching circuit in a non-operative state; operating the firstswitch of the second switching circuit in an open state; operating thesecond switch of the second switching circuit in an open state; andoperating the SCR of the second switching circuit in a non-operativestate; and wherein the method further comprises at least one of: (i)providing power from the first AC terminal to the load terminal; (ii)providing power from the battery terminal to the load terminal; and(iii) providing power from the battery terminal to the first ACterminal.
 11. The method of claim 1, wherein the step of operatingcomprises: operating the first switch of the first switching circuit ina closed state; operating the second switch of the first switchingcircuit in a closed state; operating the SCR of the first switchingcircuit in a non-operative state; operating the first switch of thesecond switching circuit in a closed state; operating the second switchof the second switching circuit in an open state; and operating the SCRof the second switching circuit in a non-operative state; and whereinthe method further comprises at least one of: (i) providing power fromthe first AC terminal to the load terminal; (ii) providing power fromthe battery terminal to the load terminal; and (iii) providing powerfrom the battery terminal to the first AC terminal.
 12. The method ofclaim 11, wherein the first AC terminal and the battery terminal areelectrically connected to the load terminal.
 13. The method of claim 1,wherein the steps of operating comprise: operating the first switch ofthe first switching circuit in an open state; operating the secondswitch of the first switching circuit in an open state; operating theSCR of the first switching circuit in a non-operative state; operatingthe first switch of the second switching circuit in a closed state;operating the second switch of the second switching circuit in a closedstate; and operating the SCR of the second switching circuit in anon-operative state; and further comprising at least one of: providingpower from the battery terminal to the load terminal; (ii) providingpower from the battery terminal to the second AC terminal; and (iii)providing power from the second AC terminal to the load terminal. 14.The method of claim 1, wherein the step of operating comprises:operating the first switch of the first switching circuit in an openstate; operating the second switch of the first switching circuit in anopen state; operating the SCR of the first switching circuit in anon-operative state; operating the first switch of the second switchingcircuit in a closed state; operating the second switch of the secondswitching circuit in an open state; and operating the SCR of the secondswitching circuit in an operative state; and wherein the method furthercomprises providing power from the second AC terminal to the loadterminal.
 15. The method of claim 14, wherein the second AC terminal andthe battery terminal are electrically connected to the load terminal.16. The method of claim 14, wherein the step of operating furthercomprises operating a fifth switch in an open state, wherein the fifthswitch is disposed between the first switch circuit and the loadterminal.
 17. The method of claim 1, wherein the controller comprises aplurality of processors.
 18. The method of claim 7, further comprisingswitching between the step (i) and the step (ii).
 19. The method ofclaim 13, further comprising switching between one of: the steps (i),(ii), and (iii) and another one of the steps (i), (ii), and (iii).